The present invention generally relates to an ultraviolet lamp assembly for killing germs or bacteria in air ventilation systems. Specifically, the present invention relates to an ultraviolet lamp including a quartz sleeve having a vented open end which results in increased or improved germicidal and bactericidal effect in systems and apparatus using ultraviolet lamps for purification or cleaning of air.
The use of certain wave lengths of ultraviolet (xe2x80x9cUVxe2x80x9d) light or radiation for its purification, germicidal and bactericidal effect is well known. UV light is commonly used to control the growth of and kill impurities in septic, water and air systems. For example, UV light or UV lamps are commonly used in heating, ventilation, and air conditioning (xe2x80x9cACxe2x80x9d or xe2x80x9cHVACxe2x80x9d) systems for purification or air cleaning purposes. UV lamps are typically installed or mounted in the air ducts of AC systems in such a manner that the UV light emitted by the lamp floods the interior of the air duct. Air flowing through that duct will be irradiated with UV radiation which will have a germicidal or bactericidal affect on the moving air thereby reducing the impurities in the air flow.
A drawback of existing UV lamps in exiting UV lamp assemblies is that the UV lamps experience diminished UV radiation output intensity over time which results in reduced germicidal and bactericidal affect of the UV lamp cleaning device. Output from such UV lamps typically reaches its maximum rated output intensity after the first few minutes of operation, after an initial heat up period of the UV lamp. The UV lamp output then typically decreases over time to a generally steady lamp intensity output as the lamp continues to operate. The steady state output is about 20% less that the maximum output obtained during the first few minutes of UV lamp operation. The drop in UV lamp output intensity is typically due to the inconsistent and variable temperature around the UV lamp that does not allow proper and uniform UV lamp cooling. The diminished UV lamp output is even more pronounced when air or water is circulated around the lamp which causes a higher rate of cooling as is well know to those of skill in the art.
Moreover, inconsistent and variable air temperatures present around a standard UV lamp result in a cooling affect that does not allow proper and uniform UV lamp cooling. In the long term, this cooling effect can adversely affect the UV lamp""s germicidal or bactericidal effect by causing the inside of the lamp to blacken or darken which in turn causes or results in a reduced UV lamp output intensity level.
In other typical UV lamp configuration, the UV lamp is mounted inside a quartz tube as an attempt to counteract known lamp-cooling issues or problems. However, such a configuration, when operated in still air, results in a larger drop in UV lamp intensity output than a standalone UV lamp. Output of a UV lamp covered by a quartz tube typically reaches its maximum rated output intensity after a few minutes of operation after the initial heat-up or warm-up period. Again, the UV lamp output will typically decrease to a generally steady lamp intensity output as the lamp continues to operate. In this configuration, the steady state output is about 35% less that the maximum output obtained during the first few minutes of UV lamp operation. Thus, the quartz outer tube results in a greater loss of UV lamp output intensity.
There is thus a need for an improved ultraviolet UV lamp assembly having improved UV lamp temperature characteristics for improved UV radiation intensity output for improved germicidal and bactericidal affect in purification, sterilization, cleaning or airflow systems.
The present invention provides a method and apparatus for an improved ultraviolet lamp assembly using an ultraviolet (UV) lamp with a vented quartz sleeve or tube having improved UV lamp temperature and cooling characteristics resulting in improved UV lamp intensity output for increased germicidal and bactericidal effect. The UV lamp assembly of the present invention can be used in systems and applications intended to purify, sterilize, clean and sanitize a medium, object or device. Further, the vented sleeve or tube is preferably a vented open end tube though other configurations may be used depending on a particular use application of the UV lamp assembly.
In one embodiment, the ultraviolet lamp assembly comprises a UV lamp housed in a vented open end quartz sleeve or tube in a portable air conditioning (AC) or heating unit. The quartz sleeve comprises a distal open end and a proximal open end. The UV lamp can be inserted into either end and secured to the tube, and the sleeve or tube is then secured to the AC or heating unit. The proximal open end of the quartz sleeve comprises a plurality of venting slots or ports that allow the air to travel into and out of the area or space between the UV lamp and the sleeve wall. The movement of air is preferably initiated by a fan or air displacer in the unit. Operation of the unit""s fan results in air flow into the quartz sleeve at a proximal sleeve base end and out through the distal open end of the quartz tube. Air can also be drawn through the tube without operation of the fan by creating a xe2x80x9cchimneyxe2x80x9d effect in the quartz tube from the heating of the air in the tube.
It is an object of the present invention to provide an ultraviolet lamp assembly that can he used in an AC or HVAC system for purification and cleaning of air flowing in the AC or HVAC system air ducts.
It is an object of the present invention to provide a UV lamp assembly with a vented quartz sleeve to provide improved and more consistent UV radiation intensity output.
It is an object of the present invention to provide a UV lamp assembly with a vented quartz sleeve with an open distal end to provide improved and more consistent UV radiation intensity output.
It is an object of the present invention to increase UV lamp life by producing more consistent and stable UV lamp temperature.
It is an object of the present invention to provide a UV lamp assembly with a vented quartz sleeve where the UV radiation intensity output is substantially uniform and constant when an associated AC fan is operating.
It is an object of the present invention to provide a shield or panel for the UV lamp assembly to improve and maintain the UV radiation intensity output of the UV lamp and where the shield or panel can be curved and extend to about 120 degrees.
It is an object of the present invention to provide a UV lamp assembly having an effective germicidal and bactericidal affect in a wavelength of about 254 nm.
It is an object of the present invention to provide a UV lamp assembly where the air around a UV lamp can be maintained in the range of 80xc2x0 F. to 100xc2x0 F. for improved germicidal and bactericidal affect in an air purification system.
It is an object of the present invention to provide an ultraviolet lamp assembly that can be used to purify air in an airflow system such as an air conditioning system in a home, hotel or building.
It is an object of the present invention to provide an ultraviolet lamp assembly that can be used to purify air in an airflow system such as a portable or standalone air conditioning unit.